closes #3

Signed-off-by: Marcel Schwittlick <marzzzel@gmail.com>
adds: bool isFinished() function

Signed-off-by: Marcel Schwittlick <marzzzel@gmail.com>
includes background substraction module

Signed-off-by: Marcel Schwittlick <marzzzel@gmail.com>
adds a radiobutton to toggle background subtraction on/off

Signed-off-by: Marcel Schwittlick <marzzzel@gmail.com>